Crown cap for containers



Dec. 28, 1943. F. J. OBRIEN CROWN CAP FOR CONTAINERS Filed Aug. 17, 1942 a. I 4 d 4% n Patented Dec. 28, 1943 UNITED, STATES PATENT .0FP' ICIE.v

CROWN CAP FOR. CONTAINERS Frank J. O'Brien, Pelham, N. Y., assignor to Continental Can Company, Inc., New York, N. Y., a corporation of New York Application August 17, 1942, Serial No. 455,111

2 Claims.

The invention relates to new and useful improvements in a closure for containers and more particularly to a closure cap of the crown cap type which includes a metal shell, an elastic pad, anda spotting material which spans the mouth of the container so as to prevent the contents thereof from contacting with the pad. It is the usual commercial practice to form the elastic pad of cork and to form the spotting material of foil or treated paper.

An object of the present invention is to shape the elastic pad so as to reduce the amount of material embodied therein without materially reducing the sealing efficiency of the pad.

A further object of the invention is to provide a sealing gasket of the above type wherein a sealing wax is so applied to the metal shell after the elastic pad is inserted therein, that the sealing wax completely spans the mouth of the container and prevents the contents of the container from contacting with the sealing pad when the container is sealed.

In the drawing which shows one embodiment of the invention,

Figure 1 is a sectional view through a. crown cap embodying my improvements;

Figure 2 is a bottom plan view of the same;

Figure 3 is a perspective view of the sealing pad before it is placed in the metal shell; and

Figure 4 is a view showing a container sealed by my improved crown cap.

While some of the principles embodied in my improved container closure may be used in other types of closures, they are particularly adapted for use in connection with a crown cap and will be so illustrated and described. The ordinary commercial crown cap includes a metal shell having a skirt which is corrugated in order to provide locking lugs which are forced beneath a shoulder on a container for securing the closure capto the container. The usual practice is to form an elastic pad from cork or like material and insert the same in the metal cap. The pad used in my improved cap is annular in horizontal cross section and said pad is so dimensioned that the radial width of the annulus is slightly greater than the sealing face of the container which is to be sealed. The pad is inserted in the metal shell and then a sealing wax is applied so as to fillthe space within the annulus and slightly overlie the inner edge portion of the annulus. This overlying portion is so dimensioned as to completely span the mouth of the container, thus preventing the contents of the container from contacting with the cork pad.

Referring more in detail to the drawing, the

crown cap is shown applied to a bottle I, the neck portion of which is provided with a sealing face,

2 and a holding shoulder 3.. The crown cap embodying my improvements includes a metal shell 4 having a depending skirt 5. The lower portion of the skirt is corrugated so as to provide spaced lugs 8 which are forced underneath the shoulder on the neck of the bottle for securingthe capto the bottle. These features are all of usual construction and it is not thought that further detailed description thereof is necessary.

The elastic pad used in connection with the metal shell is preferably formed of ground cork,

the particles of which are secured together by a suitable cement. The pad is of annular shape in cross section. In Figure 3 the pad is shown,

at 1 in the drawing. The radial width of the annulus indicated at 8 is slightly greater than the width of the sealing face 2 of the bottle. This cork pad is dimensioned so that it fits within the metal cap and can be secured therein in any suitable-wayeither by frictional grip with the skirt of the cap or by a suitable cement. The cut-out portion forming the annulus is of such diameter that the inner wall 8 of the annulus is substantially over the inner wall of the neck of the bottle. After the pad is inserted in the metal cap, then a sealing wax is applied which fills tne space within the annulus and slightly overlies the edge portion of the annulus. The sealing wax will adhere to the metal cap and will cover the inner side walls 8 of the annulus. The wax overlies the inner edge of the annulus as indicated at H) in Figures 1 and 2.

A sealing wax of the type described in the patent granted to A. L. Kronquest, May 10, 1938, No. 2,117,180, is very eificient for filling the opening in the gasket and overlying the under edge portion thereof. This wax described in-the patent is an amorphous petrolatum wax-and has a melting point well above the temperature utilized in the pasteurizing of beverages in sealed containers. It is very ductile and will not fracture even when the sealed container'is maintained at a refrigerating temperature."-*A suitame resin I filler may be mixed with the wax if desired, and

other types of sealing waxes may be used.

It will be noted that the wax overlies the under inner edge portion of the gasket and when the cap is applied to the bottle the waxwill extend to the sealing contact between the sealing facev of the bottle and the gasket and therefore span the mouth of the bottle so that the contents ofthe bottle will not at any time come into contact with the cork insert. While the wax laps over the inner edge portion of the gasket, still the greater portion of the under surface of the gasket is exposed so as to contact with the sealing face of the bottle and produce a very eflicient seal when the cap is secured to the bottle. The pressure against the wax when the cap is applied, although the sealing pad yields to form the seal, will maintain its integrity and will not fracture so as to form openings or cracks through which the contents of the bottle might reach the pad.

By.forming the gasket in the manner described, it may be made of the usual thickness employed in connection with cork insertsand therefore the same efiicient sealing of the bottle obtained as with a cork disk which extends all the way across the mouth of the bottle. By cutting out the center portion of this disk and forming the annulus, the amount of material employed in the making of the pad is greatly reduced from that which would be necessary if the pad was a continuous disk. When the cut-out portion is replaced with wax, a gasket is formed which is just as efiicient as the full continuous disk gasket. Furthermore, when this wax is used so as to overlie the inner edge portion of the under face of the gasket, no spotting material is necessary. The

wax itself performs the function of the spotting material and prevents the contents of the bottle from contacting with the pad.

Instead of a cork pad, other forms of elastic pads may be used to advantage, and as noted, other forms of wax may be utilized for th filling of the annulus and for covering the inner edge portion thereof without departing from the spirit of the invention as set forth in the appended claims. It will also be obvious that the invention may be used in other types of closures than the crown cap with equal efficiency.

What I claim is:

1. An article of manufacture, a cap of the crown type for containers having a pouring mouth surrounded by a sealing surface comprising a metal shell having a depending skirt shaped to provide holding lugs, an annular sealing gasket fitting within the metal cap and having a radial width substantially equal to the sealing face of the container, a sealing wax filling the opening in the gasket and overlying the inner edge portion only of the gasket, said overlying portion being dimensioned so as to completely span the mouth of the container and prevent th contents of the container from contacting with the sealing gasket.

2. An article of manufacture, a cap of the crown type for containers having a pouring mouth surrounded by a sealing surface comprising a metal shell having a depending skirt shaped to provide holding lugs, an annular sealing gasket of cork fitting within said metal cap and having a radial width substantially equal to the width of the sealing face of the container, and an amorphous petrolatum sealing wax filling the opening in the gasket and overlying the edge portion only of the gasket, said overlying portion being dimensioned so as to completely span the mouth of the container and prevent the contents of the container from contacting with the sealing gasket.

FRANK J. OBRIEN. 

